The Brihanmumbai Municipal Corporation (BMC)’s tree census is finally coming to a close. The much-awaited census report, delayed by two years, surveyed 26.36 lakh trees in the city till May this year and will be submitted by next month, said the civic body’s tree authority.

The census data will be uploaded on the BMC’s website so that people can easily access it. The data is also expected to help those researching the city’s green cover. The last tree census in the city, carried out in 2008, had recorded 19.17 lakh trees. In 2015, the BMC’s garden department had claimed a 40 per cent increase in the number of trees in the island city and parts of Matunga, Parel, Malad and Goregaon.

The figure had, however, sparked a controversy as the census allegedly included 33,202 dead trees and 1.59 lakh subabhul trees, a foreign species known to be weeds and invaders, that led to environmentalists demanding a change in the tree census methodology.

Dr Nilesh Baxi, environmentalist and former member of the tree authority, alleged that the tree census done by the civic body was an eyewash. “While they counted 33,000 dead trees in 2015, I had pointed out that in the 2008 census, they had counted around 92,000 dead trees. When I objected, I was told even dead tress are of use,” he said.

The latest census used Trimble GPS units to note the location of a tree. This information, along with a unique ID for each tree with its characteristics, will be published on the civic body’s geographic information system (GIS) map.

Apart from numbers, age and species of the trees and other information — such as whether the tree is diseased, has been mechanically cut, and has a cement collar around it — has also been recorded in the census, which was supposed to get over by 2015-end.

BMC’s Superintendent of Gardens, Jitendra Pardeshi, said: “The delay has been for various reasons, the biggest factor being non-availability of base map. Later, counting was stalled during the monsoon. Unless we have tree counts from all the 24 wards, we cannot make it public. The census is in its final lap now, where we are cross-checking all the data and information. This will be completed in 15-20 days. All this information will be uploaded on our website. This will also help researchers’ studies on the city’s green cover. It would be done within the next one month.”

According to officials of the garden department, the GIS made it easier to know the location of rare species.Preliminary data till May 2017 show the highest number of trees is in the P-North (Malad) ward, which has 2.8 lakh trees, followed by the K-East (Andheri, Vile Parle) ward, which has 1.7 lakh trees. So far, the census has recorded 340 species of trees in Mumbai, of which, 140 are endangered, Pardeshi said.

Areas where rare trees were recorded during the survey are Mumbai University’s Kalina campus, Veermata Jijabai Bhosale Udyan at Byculla and the Colaba Woods Garden. This is the first time that the green cover at the Aarey Milk Colony has been included in the census.

The area has 4.86 lakh trees and 240 species. Environmentalist Stalin D, however, said: “Aarey is a natural forest with over 5 lakh trees. The BMC did not conduct any survey in the past six decades of the trees in Aarey. Now, they are adding this huge number from this zone just to cover up the losses in other urban areas. If you exclude Aarey, you will see that the tree cover has actually decreased. In fact, more than 2,000 trees died due to concretisation and various projects.”